Add remove form elements with tabledrag and ajax drupal 8.x

AddMoreRemoveForm.php

<?php

namespace Drupal\experiments\Form;

use Drupal\Core\Form\FormBase;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Component\Utility\SortArray;

/**
 * Class AddMoreForm.
 *
 * @package Drupal\experiments\Form
 */
class AddMoreForm extends FormBase {

  /**
   * {@inheritdoc}
   */
  public function getFormId() {
    return 'add_more_form';
  }

  /**
   * {@inheritdoc}
   */
  public function buildForm(array $form, FormStateInterface $form_state) {
    $form['accordions'] = [
      '#type' => 'table',
      '#tree' => true,
      '#prefix' => '<div id="accordions-wrapper">',
      '#suffix' => '</div>',
      '#header' => array(t('Item'), t('Weight'), t('Accordion content'), t('Actions')),
      '#tabledrag' => array(
        array(
          'action' => 'order',
          'relationship' => 'sibling',
          'group' => 'mytable-order-weight',
        ),
      ),
    ];

    $weights = $form_state->getValue('accordions');
    if (empty($weights)) {
      $weights[] = [
        'weight' => 0,
        'accordion' => [],
      ];
    }
    uasort($weights, 'Drupal\Component\Utility\SortArray::sortByWeightElement');
    foreach ($weights as $delta => $weight) {
      // TableDrag: Weight column element.
      $form['accordions'][$delta]['#attributes']['class'][] = 'draggable';
      $form['accordions'][$delta]['#weight'] = isset($weight['weight'])?$weight['weight']:0;
      $form['accordions'][$delta]['item'] = array(
        '#plain_text' => isset($weight['weight'])?$weight['weight']:0
      );
      $form['accordions'][$delta]['weight'] = array(
        '#type' => 'weight',
        '#title' => t('Weight for @title', array('@title' => 'accordion')),
        '#title_display' => 'invisible',
        '#attributes' => array('class' => array('mytable-order-weight')),
        '#default_value' => isset($weight['weight'])?$weight['weight']:0
      );
      $form['accordions'][$delta]['accordion'] = [
        '#type' => 'details',
        '#tree' => true,
        '#title' => t('Accordion @counter', ['@counter' => ($delta+1)]),
        '#collapsible' => true,
      ];
      $form['accordions'][$delta]['accordion']['title'] = [
        '#type' => 'textfield',
        '#title' => t('Title'),
      ];
      $form['accordions'][$delta]['accordion']['text'] = [
        '#type' => 'text_format',
        '#title' => t('Name'),
      ];
      if (count($weights) > 1) {
        $form['accordions'][$delta]['delete'] = [
          '#type' => 'submit',
          '#title' => t('Remove'),
          '#name' => 'delete_' . $delta,
          '#value' => 'Remove',
          '#submit' => ['::ajaxSubmit'],
          '#ajax' => [
            'callback' => '::addMoreSet',
            'wrapper' => 'accordions-wrapper',
          ]
        ];
      }else{
        $form['accordions'][$delta]['delete'] = [];
      }
    }
    
    $form['add'] = [
      '#type' => 'submit',
      '#title' => t('Add accordion'),
      '#value' => t('Add more'),
      '#submit' => ['::ajaxSubmit'],
      '#ajax' => [
        'callback' => '::addMoreSet',
        'wrapper' => 'accordions-wrapper',
      ]
    ];
    return $form;
  }

  public function addMoreSet(array &$form, FormStateInterface $form_state) {
    return $form['accordions'];
  }

  /**
   * {@inheritdoc}
   */
  public function ajaxSubmit(array &$form, FormStateInterface $form_state) {
    $weights = $form_state->getValue('accordions');
    $parents = $form_state->getTriggeringElement()['#parents'];
    if (isset($parents[0]) && $parents[0] == 'add') {
      $weights[] = [
        'weight' => 0,
        'accordion' => [],
      ];
    }
    if (isset($parents[2]) && $parents[2] == 'delete') {
      unset($weights[$parents[1]]);
    }
    
    $form_state->setValue('accordions', $weights);
    $form_state->setRebuild(TRUE);
  }
  
  /**
   * {@inheritdoc}
   */
  public function submitForm(array &$form, FormStateInterface $form_state) {
    
  }

}